The reason is that when i add the widget url to our sharepoint site it seems to be using Flash.
And we all know how the browsers are reacting to flash these days with warning and etc. Not a good customer experience in a ncie sharepoint site.

I am using v8 of course in this scenario right now which seems to be flash-based, correct?

Not a direct problem but when we show our customers backupstate on our sharepoint site the web browsers seems to not be happy with all the flash elements (one flasheelement for each customer)
I have uploaded a image here that show or sharepoint during loading from the widgets from our customers site: http://postimg.org/image/j45fkk9hr/

Yes, it will just be fore a couple of seconds, after that everything is fine.
I have reproduced it on 5 different workstations with both Windows and Linux as operatingsystem abd we have tried Firefox, Chrome, Internet Explorer as browsers.
I guess it can be that we not have an up to date flash player too, i will check that.

Anyway, not a particular fan of flash these days, doesn't look good when browsing from ipad f.ex

Frank, just a quick update for you. Seems like there was obsolete check for Flash on the main page of Veeam ONE Reporter. We will try to squeeze in this change in v9, so you will not have this issue any more.